JP2006205584A - Rubber kneading equipment and rubber kneading method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide rubber kneading equipment capable of stabilizing the quality of a rubber compound when silica is kneaded with the rubber compound. <P>SOLUTION: The rubber kneading equipment is equipped with a kneading means 1, a metering means 2, a water content measuring means 4 for measuring the water content of silica S<SB>1</SB>in a process for feeding the silica S<SB>1</SB>metered by the metering means 2 to the kneading means 1, a water supply means 5 for supplying water to the silica S<SB>1</SB>metered by the metering means 2, and a control means 6 for controlling these metering means 2, the water content measuring means 4 and the water supply means 5. This rubber kneading equipment is used to calculate the deficient moisture amount to a target water content on the basis of the actual water content measured by the water content measuring means 4 and the weight of the silica S<SB>1</SB>measured by the metering means 2 and the water supply amount from the water supply means 5 is controlled based on the deficient moisture amount while the silica S<SB>1</SB>which receives water is kneaded with the rubber compound along with a silane coupling agent by the kneading means 1. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a rubber kneading equipment and a rubber kneading method, and more specifically, when kneading silica in a rubber compound, the reaction between silica and a silane coupling agent is stabilized by keeping the water content of silica constant, The present invention relates to a rubber kneading equipment and a rubber kneading method capable of stabilizing the quality of a rubber compound.

  Conventionally, carbon black has been used as a filler for rubber. In recent years, silica has attracted attention as a low heat-generating filler. Silica tends to aggregate particles due to hydrogen bonding of silanol groups which are surface functional groups, and the dispersibility of silica particles in rubber is low. Therefore, when silica is compounded in a rubber compound, a silane coupling agent is used in combination. In addition, when kneading silica into a rubber compound, it is important to control the reaction between silica and the silane coupling agent in order to achieve the original performance and to stabilize the quality. In particular, since moisture adsorbed on the silica surface contributes to the reactivity, it is possible to control the reaction between silica and the silane coupling agent by controlling the moisture content of silica (for example, Patent Document 1). reference).

By the way, although the water content of the precipitated silica (percentage of water content relative to the amount of dry silica) is usually 4 to 6%, it is difficult to accurately grasp the water content during kneading. Therefore, if the water content of silica varies during kneading, there is a problem that the reaction during kneading becomes unstable. In addition, silica is weighed in a state containing moisture, but the moisture is volatilized during kneading. And the quality of the rubber compound becomes unstable.
JP 2000-290431 A

  The object of the present invention is to stabilize the reaction of silica and the silane coupling agent and to stabilize the quality of the rubber compound by keeping the water content of the silica constant when kneading silica into the rubber compound. Another object is to provide a rubber kneading facility and a rubber kneading method.

  In order to achieve the above object, the rubber kneading equipment of the present invention comprises a kneading means, a measuring means, and a moisture content for measuring the moisture content of the silica in the course of conveying the silica measured by the measuring means to the kneading means. Measurement means, water supply means for supplying water to the silica measured by the measurement means, and control means for controlling the measurement means, the moisture content measurement means and the water supply means, Calculating a deficient moisture amount with respect to a target moisture content on the basis of the actual moisture content measured by the rate measuring means and the weight of the silica measured by the measuring means, and supplying water from the water supply means based on the deficient moisture amount The quantity is controlled.

  Further, the rubber kneading method of the present invention for achieving the above object is to measure the moisture content of the silica in the course of conveying the silica measured by the kneading means, the measuring means, and the measuring means to the kneading means. Using a rubber kneading facility comprising water content measurement means, water supply means for supplying water to the silica measured by the measurement means, and control means for controlling the measurement means, water content measurement means and water supply means Calculating a deficient moisture amount with respect to a target moisture content based on the actual moisture content measured by the moisture content measuring means and the weight of the silica measured by the measuring means; and the water supply means based on the insufficient moisture amount The amount of water supplied from the control unit is controlled, and the silica that receives the supplied water is kneaded into the rubber compound together with the silane coupling agent in the kneading means.

  In the present invention, the moisture content measuring means for measuring the moisture content of the silica in the process of conveying the silica measured by the measuring means to the kneading means, and the water supply means for supplying water to the silica measured by the measuring means, And calculating a deficient moisture amount relative to the target moisture content based on the actual moisture content measured by the moisture content measuring means and the silica weight measured by the weighing means, and from the water supply means based on the insufficient moisture amount Supply an appropriate amount of water. That is, prior to kneading, the moisture content of silica is measured, and the moisture content is brought close to the target value. Therefore, when the silica is kneaded into the rubber compound, the reaction between the silica and the silane coupling agent can be stabilized and the quality of the rubber compound can be stabilized.

  In the present invention, it is preferable to provide a dispersion means for dispersing the water supplied from the water supply means in the silica before the kneading means. In this way, by dispersing the water supplied from the water supply means in the silica before the kneading means, the reaction between the silica and the silane coupling agent can be further stabilized.

  Further, the control means calculates the amount of insufficient silica in terms of dry weight based on the actual moisture content measured by the moisture content measuring means and the weight of silica measured by the weighing means, and based on the amount of insufficient silica. It is preferable to control the additional charge of silica from the metering means. Thus, the quality of the rubber compound can be further stabilized by additionally adding silica from the measuring means based on the amount of insufficient silica.

  Hereinafter, the configuration of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 shows a rubber kneading facility according to a first embodiment of the present invention. As shown in FIG. 1, this rubber kneading equipment includes a closed mixer (kneading means) 1, a weighing hopper (measuring means) 2, a conveyor (conveying means) 3, an infrared spectrophotometer (moisture content measurement). Means) 4, a water supply device (water supply means) 5, and a control device (control means) 6.

  The mixer 1 is an apparatus for kneading a rubber compound and a compounding agent such as silica in a sealed space. As the kneading means, a closed mixer is preferably used, but its structure is not particularly limited.

  The weighing hopper 2 is a device that stores a material (silica S) to be supplied and discharges the material in a necessary amount. As the weighing means, it is preferable to use a weighing hopper, but the structure is not particularly limited.

The conveyor 3 is a device that conveys the silica S ₁ measured by the measuring hopper 2 to the mixer 1. Although it is preferable to use a conveyor as the conveying means, the structure is not particularly limited.

The infrared spectrophotometer 4 is a device for measuring the moisture content of the silica S _{1 in} a non-contact manner in the process of transporting the silica S ₁ measured by the measuring hopper 2 to the mixer 1. That is, the infrared spectrophotometer 4 irradiates the silica S ₁ with infrared rays, and continuously measures the strength of the hydroxyl group (OH) based on the infrared absorption spectrum. In this case, the water content of the silica S ₁ can be determined from the strength of the hydroxyl group. As the moisture content measuring means, it is preferable to use the infrared spectrophotometer 4, but the structure is not particularly limited. As another example of the moisture content measuring means, a heating weight loss device 14 can be used. The heating weight loss device 14 is a device that measures the weight change of the sample T with the balance 14b while heating the sample T collected from the silica S in the weighing hopper 2 with the heater 14a to remove moisture. In this case, the moisture content of the silica S, that is, the moisture content of the measured silica S ₁ can be obtained from the initial weight and the reduced amount of the sample T.

The water supply device 5 is a device that supplies water to the silica S ₁ measured by the measurement hopper 2. The water supply means is required to be able to freely adjust the water supply amount, but its structure is not particularly limited. However, in consideration of the dispersibility of water in silica S ₁ , it is preferable to provide a nozzle that enables water spraying and spraying.

The control device 6 is a device that controls the weighing hopper 2, the infrared spectrophotometer 4, and the water supply device 5. More specifically, the control device 6 calculates the deficient moisture amount with respect to the target moisture content based on the actual moisture content measured by the infrared spectrophotometer 4 and the weight of the silica S ₁ measured by the weighing hopper 2. The amount of water supplied from the water supply device 5 is controlled based on the amount of deficient moisture. That is, prior to kneading, the moisture content of silica S ₁ is measured, and the moisture content is brought close to the target value.

Next, a rubber kneading method using the above-described rubber kneading apparatus will be described. First, the weighing hoppers to discharge the silica S ₁ of the required amount from 2 onto the conveyor 3, hydrated silica S ₁ by infrared spectrophotometer 4 silica S ₁ which is weighed by the weighing hoppers 2 in the course of conveyance to the mixer 1 Measure the rate. At this time, the control device 6 calculates the deficient moisture amount with respect to the target moisture content based on the actual moisture content measured by the infrared spectrophotometer 4 and the weight of the silica S ₁ measured by the weighing hopper 2. The amount of water supplied from the water supply device 5 is controlled based on the amount of insufficient moisture.

For example, when the weight of silica S ₁ measured by the weighing hopper 2 is 50.00 kg and the water content of silica S ₁ measured by the infrared spectrophotometer 4 is 4%, the water content is 1.92 kg. The dry weight of silica is 48.08 kg. Here, when the target moisture content is set to 6%, the deficient moisture amount is about 0.96 kg. Therefore, the amount of water supplied from the water supply device 5 may be 0.96 kg.

Thereafter, the silica S ₁ that has been supplied with water is put into the mixer 1, and is kneaded into the rubber compound together with the silane coupling agent in the mixer 1. At that time, since the moisture content of the silica S ₁ is adjusted to the target value, the reaction between the silica and the silane coupling agent can be stabilized and the quality of the rubber compound can be stabilized.

  The polymer of the rubber compound contains 50 to 100 parts by weight of styrene-butadiene rubber (SBR) obtained by melt polymerization or emulsion polymerization in 100 parts by weight of the polymer, and butadiene rubber (BR), natural rubber (NR), etc. as optional components It is preferable to contain 0 to 50 parts by weight of the diene rubber. On the other hand, the blending amount of silica is preferably 20 to 100 parts by weight with respect to 100 parts by weight of the polymer, and the blending amount of the silane coupling agent is preferably 5 to 12% by weight with respect to the silica weight.

  As silica, it is possible to use dry method silica (anhydrous silicic acid), precipitation method silica (hydrous silicic acid) and the like. For example, the water content of the precipitated silica is usually 4 to 6%, but the target water content is desirably set to 6 to 10% by weight. If the water content at the time of kneading is less than 6% by weight, the effect of stabilizing the reaction between silica and the silane coupling agent becomes insufficient. Conversely, if the water content exceeds 10% by weight, the kneading time becomes longer. That is, by setting the target moisture content, the reaction can be stabilized while shortening the kneading time.

  FIG. 2 shows a rubber kneading facility according to the second embodiment of the present invention. Since this embodiment is obtained by adding dispersion means to the first embodiment, the same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

In FIG. 2, a dispersing device (dispersing means) 7 and a conveyor (conveying means) 8 associated with the dispersing device (dispersing means) 8 are disposed in the preceding stage of the mixer 1. The dispersion device 7 is a device that disperses water supplied from the water supply device 5 in silica. By adding such a dispersing device 7 and dispersing the water supplied from the water supply device 5 in the silica S ₁ before the mixer 1, the reaction between the silica and the silane coupling agent is further stabilized. Can do.

  FIG. 3 shows a rubber kneading facility according to the third embodiment of the present invention. Since this embodiment is different from the control method in the first embodiment, the same components as those in FIG. 1 are denoted by the same reference numerals, and detailed description thereof is omitted.

In FIG. 3, the control device 6 calculates the deficient moisture amount with respect to the target moisture content based on the actual moisture content measured by the infrared spectrophotometer 4 and the weight of the silica S ₁ measured by the weighing hopper 2. In addition to controlling the amount of water supplied from the water supply device 5 based on the insufficient amount of water, the actual water content measured by the infrared spectrophotometer 4 and the weight of the silica S ₁ measured by the measuring hopper 2 The amount of insufficient silica in terms of dry weight is calculated based on the above, and the additional amount of silica S supplied from the weighing hopper 2 is controlled based on the amount of insufficient silica.

For example, when the weight of silica S ₁ measured by the weighing hopper 2 is 50.00 kg and the water content of silica S ₁ measured by the infrared spectrophotometer 4 is 4%, the water content is 1.92 kg. The dry weight of silica is 48.08 kg. Here, assuming that the required dry silica weight is 50.00 kg and the target moisture content is set to 6%, the added silica S ₂ weight is about 1.92 kg, The deficient moisture amount (water supply amount) is about 1.08 kg. The added silica S ₂ also contains about 4% moisture, but this moisture is negligible with respect to the total amount of silica and can be ignored. Of course, it is also possible to correct the silica additional input amount and the water supply amount in consideration of the moisture contained in the silica S ₂ .

It is a side view which shows the rubber kneading equipment which consists of 1st Embodiment of this invention. It is a side view which shows the rubber kneading equipment which consists of 2nd Embodiment of this invention. It is a side view which shows the rubber kneading equipment which consists of 3rd Embodiment of this invention.

Explanation of symbols

1 Mixer (kneading means)
2 Weighing hopper (measuring means)
3,8 Conveyor (conveying means)
4 Infrared spectrophotometer (moisture content measuring means)
5 water supply equipment (water supply means)
6. Control device (control means)
7 Dispersing means (dispersing device)
14 Heat loss device (moisture content measuring means)

Claims (6)

A kneading means, a measuring means, a moisture content measuring means for measuring the moisture content of the silica in the process of conveying the silica measured by the measuring means to the kneading means, and the silica measured by the measuring means Water supply means for supplying water, and control means for controlling these measurement means, moisture content measurement means, and water supply means, in which the actual moisture content measured by the moisture content measurement means and the measurement means A rubber-kneading facility that calculates a deficient moisture amount with respect to a target moisture content based on the weight of silica measured in step 1 and controls a water supply amount from the water supply means based on the deficient moisture amount. The rubber kneading equipment according to claim 1, further comprising a dispersing means for dispersing the water supplied from the water supplying means in silica in a stage preceding the kneading means. In the control means, a deficient silica amount in terms of dry weight is calculated based on the actual moisture content measured by the moisture content measuring means and the silica weight measured by the weighing means, and based on the deficient silica amount. The rubber kneading equipment according to claim 1, wherein an additional amount of silica added from said metering means is controlled. A kneading means, a measuring means, a moisture content measuring means for measuring the moisture content of the silica in the process of conveying the silica measured by the measuring means to the kneading means, and the silica measured by the measuring means Using a rubber kneading facility provided with water supply means for supplying water and these measurement means, moisture content measurement means and control means for controlling the water supply means, the actual moisture content measured by the moisture content measurement means and the measurement Based on the silica weight measured by the means, the amount of moisture shortage with respect to the target moisture content is calculated, the amount of water supplied from the water supply means is controlled based on the amount of moisture shortage, and the kneading means A rubber kneading method wherein kneading is carried out in a rubber compound together with a silane coupling agent. The rubber kneading method according to claim 4, wherein water supplied from the water supply means is dispersed in silica at a stage preceding the kneading means. Based on the actual moisture content measured by the moisture content measuring means and the silica weight measured by the weighing means, the amount of insufficient silica in terms of dry weight is calculated, and based on the insufficient silica amount, The rubber kneading method according to claim 4, wherein the additional amount of silica added is controlled.

Images